73 merc carb issues

biddle1950

Seaman Apprentice
Joined
Jan 8, 2010
Messages
30
73 merc 50. started good, but no top end. rebuilt carbs, good top end but hard starting. does anyone have the base carb adjustment and/or timing. neighbors boat and trying to help.
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,036
Re: 73 merc carb issues

Normally on Mercs, the initial carb setting is 1-1/2 turns open from light seating. After warm up, set to best idle speed and then start to richen the mixture by opening top carb 1/8 turn and testing acceleration. Repeat with bottom carb, testing after each adjustment. Yu want smooth acceleration and reasonable idle. it is a compromise setting.
 
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